This invention is directed to a novel dry cleaning process. More particularly, the invention is directed to a process for dry cleaning substrates in an environmentally friendly solvent whereby an additive is employed to soften and/or reduce wrinkles in the substrates being cleaned.
In many cleaning applications, it is desirable to remove contaminants (e.g., stains) from substrates, like metal, ceramic, polymeric, composite, glass and textile comprising substrates. Particularly, it is highly desirable to remove contaminants from fabrics, like clothing, whereby such contaminants include dirt, salts, food stains, oils, greases and the like.
Typically, dry cleaning systems use organic solvents, like chlorofluorcarbons, perchloroethylene, and branched hydrocarbons to remove contaminants from substrates. In response to environmental concerns, however, other dry cleaning systems have been developed that use biodegradable hydrocarbons, silicone comprising solvents, as well as inorganic solvents like densified carbon dioxide.
The cleaning systems that employ environmentally friendly solvents generally employ a cleaning surfactant and a polar solvent so that a reverse-micelle may be formed to trap the contaminant targeted for removal.
When dry cleaning in the manner described above, it is not uncommon for the resulting cleaned substrate to appear wrinkled and/or not feel soft to the touch of the hand.
Since consumers desire the feel of soft clothing that is wrinkle free, and care to preserve the environment, it is of increasing interest to develop a dry cleaning method that is environmentally friendly and results in substrates that are, after cleaning, soft, have reduced wrinkle formation, or both. This invention, therefore, is directed to a dry cleaning process for dry cleaning substrates in an environmentally friendly solvent whereby an additive is employed to improve the characteristics of in the substrates being cleaned.
Efforts have been disclosed for dry cleaning garments. In U.S. Pat. No. 5,683,977, a dry cleaning system using densified carbon dioxide and a surfactant adjunct is disclosed.
Still other efforts have been disclosed for dry cleaning cloths. In U.S. Pat. No. 6,131,421, a dry cleaning system with a polysiloxane surfactant is disclosed.
None of the references above disclose a method for dry cleaning in a friendly environment while at the same time reducing, for example, wrinkle formation.
In a first aspect, the present invention is directed to a method for dry cleaning substrates comprising, in no particular order, the steps of:
contacting a substrate with a solvent selected from the group consisting of a solvent which is a gas at standard temperature and pressure, a biodegradable functionalized hydrocarbon and a silicon comprising solvent; and
contacting the substrate with an additive, the additive comprising a first portion which is solvent phobic and a second portion which is solvent philic; and
allowing the second portion to impart a lubricious soft hand on the substrate, or to lubricate fiber surfaces of the substrate to reduce wrinkle formation, or both.
In a second aspect, this invention is directed to a method for reducing at least one negative clothing feature selected from the group consisting of pill formation, color loss and shape distortion, comprising, in no particular order, the steps of:
contacting a substrate with a solvent selected from the group consisting of a solvent which is a gas at standard temperature and pressure, a biodegradable functionalized hydrocarbon and a silicon comprising solvent;
contacting the substrate with an additive, the additive comprising a first portion which is solvent phobic and a second portion which is solvent philic; and
allowing the second portion to coat fibers on the substrate in order to reduce pill formation, reduce color loss and/or reduce shape distortion.
In a third aspect, the present invention is directed to a dry cleaning system comprising an additive for improving substrate characteristics.
Lubricious soft hand is defined to mean a perceived softness improvement by a panel of evaluators assessing the softness of cleaned fabrics.